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Serial Network Flow Monitor (SNFM)
04.26.13

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Overview | Description | Applications | Operations | Results | Publications | Imagery

Experiment Overview

This content was provided by Carl Konkel, and is maintained in a database by the ISS Program Science Office.

Brief Summary

Using a commercial software CD, Serial Network Flow Monitor (SNFM) monitors the payload local area network (LAN) to analyze and troubleshoot LAN data traffic. Validating LAN traffic models may allow for faster and more reliable computer networks to sustain systems and science on future space missions.

Principal Investigator(s)

  • Carl Konkel, Boeing, Houston, TX, United States

    • Co-Investigator(s)/Collaborator(s)

    Information Pending

    Developer(s)

    Boeing, Houston, TX, United States

    Sponsoring Space Agency

    National Aeronautics and Space Administration (NASA)

    Sponsoring Organization

    Human Exploration and Operations Mission Directorate (HEOMD)

    Research Benefits

    Information Pending

    ISS Expedition Duration:

    April 2004 - September 2014

    Expeditions Assigned

    9,10,11,12,19/20,21/22,23/24,25/26,27/28,29/30,31/32,33/34,35/36,37/38,39/40

    Previous ISS Missions

    SNFM is a continuing investigation which has been performed on ISS Expeditions 9 and 10.

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    Experiment Description

    Research Overview

    • This experiment studies the function of the computer network onboard the ISS.


    • On-orbit packet statistics are captured and used to validate ground based medium rate data link models and enhance the way that the local area network (LAN) is monitored.


    • This information will allow monitoring and improvement in the data transfer capabilities of on-orbit computer networks.

    Description

    The Serial Network Flow Monitor (SNFM) experiment attempts to characterize the network equivalent of traffic jams on board ISS. The SNFM team is able to specifically target historical problem areas including the SAMS (Space Acceleration Measurement System) communication issues, data transmissions from the ISS to the ground teams, and multiple users on the network at the same time. By looking at how various users interact with each other on the network, conflicts can be identified and work can begin on solutions.

    SNFM is comprised of a commercial off the shelf software package that monitors packet traffic through the payload Ethernet LANs (local area networks) on board ISS.

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    Applications

    Space Applications

    Extends ISS accommodations to sub-rack payloads. Provides a set of standard interfaces and resources for sub-rack payloads. Supports the simultaneous and independent operations of multiple payloads within the rack. Accommodates multiple science disciplines.

    Earth Applications

    Locating and correcting computer network problems may alleviate the data downlinking issues. This will provide the scientists on the ground with the data that is necessary for the analysis of the data for their experiments. Some of the results from these experiments may make significant improvements in many areas of human life.

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    Operations

    Operational Requirements

    A Commercial Off the Shelf software package is loaded from a CD-ROM to an EXPRESS rack laptop computer. SNFM ground personnel typically coordinate with other network users and/or the POIC to determine when the events they wish to monitor will occur. The SNFM investigation monitors only the medium rate data link (MRDL).

    Operational Protocols

    Crew loads software onto an EXPRESS Laptop Computer (ELC) for Payload LAN monitoring. Files are downlinked by ground command. Operation of SNFM by the crew will require power up of the EXPRESS Laptop and activation of the selected SNFM Autocapture template. Once activated, SNFM will monitor the network and capture packet statistics until its buffer has filled.

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    Results/More Information

    SNFM data are still being analyzed, and will provide "lessons learned" for ongoing network operations on space station and future spacecraft systems. (Evans et al. 2009)

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    Related Websites

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    Imagery

    image This image shows the software CD-ROM which contains the SNFM program. Image courtesy of Nasa, Johnson Space Center.
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    image This image shows an example of network loading displayed graphically. Image courtesy of NASA, Johnson Space Center.
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    Information provided by the investigation team to the ISS Program Scientist's Office.
    If updates are needed to the summary please contact JSC-ISS-Program-Science-Group. For other general questions regarding space station research and technology, please feel free to call our help line at 281-244-6187 or e-mail at JSC-ISS-Research-Helpline.
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